package LeetCode;

public class Num278  extends VersionControl {
    public int firstBadVersion(int n) {
        int left=1;
        int right=n;
        while (left<right){
            int mid=left+(right-left)/2;
            if(isBadVersion(mid)){
                right=mid;
            }else {
                    left = mid + 1;

            }
        }
        return left;
    }
}
